Recent studies have shown that polyphenols of cocoa beans may have beneficial effects to human health. Polyphenols can reduce the risk of chronic diseases such as cardiovascular diseases and cancers. Polyphenols and polyphenol-containing natural products such as cocoa beans could therefore be used in functional food or medicine.
Freshly harvested cocoa beans contain high levels of low molecular weight polyphenols that are oxidized into polymeric forms once the natural pod shell is opened. These polymeric polyphenols are no longer available for bio-absorption. Since there is no economically acceptable process that would avoid polyphenol polymerization caused by oxidation, there is a need to explore such processes. Most preferably, such processes would at the same time maintain other properties of natural cocoa beans.
EP 0 806 147 A1 describes a method of removing off-flavor notes from cocoa products. The method disclosed in this reference uses fermented cocoa beans that are steamed at elevated temperatures to produce acid-reduced roasted cocoa.
WO 2006/028360 A1 is directed to a method for preparing cocoa beans, which method comprises the steps of steaming roasted shelled cocoa beans, exposing them to air flow at a temperature ranging from 80-170° C. and treating said shelled cocoa beans with an oil.
JP 61195647 A describes the production of bitter chocolate, the production comprising the collection of raw cocoa beans from cocoa fruits as well as fermenting and drying cocoa beans before steaming, roasting and grinding by conventional procedures.
U.S. Pat. No. 5,395,635 reveals a method of producing white cocoa nibs. To avoid color-formation, cocoa beans of the colorless type are heated in hot water or water vapor containing an acidic, alkaline or alcoholic substance without being subjected to fermentation or after being slightly fermented. Nibs of the beans are thereby prevented from undergoing a color change.
WO 2005/004619 A2 is directed to whole roasted cocoa bean products and aims at providing an efficient manufacturing process for yielding high quality whole cocoa bean powder which has a low microbiological content.
WO 2005/115160 A1 describes a process for producing cocoa polyphenol concentrate comprising the step of blanching unfermented cocoa beans in water at a temperature in the range of from 85-100° C.
However, none of the processes described in the prior art allows to economically reduce the polyphenol oxidase activity in cocoa beans to yield cocoa beans with high polyphenol content and at the same time to maintain other natural characteristics of said cocoa beans such as polyphenol profile.